My grandmother is 72 and recently had surgery to remove thyroid cancer, and we recently learned that it has metastasized to the lungs, despite the fact that she has been seeing a doctor regarding her cancer on a regular basis for the past 8 years. She had a surgeon that discouraged her from surgery for two years, despite her oncologist encouraging surgery, and her surgeon actually had the gall to ask her "Well, how much longer do you want to live?" She had to change hospitals completely to find a surgeon who supported the surgical option, and they did a fantastic job. Unfortunately, the cancer had already spread by that time. She'll be having radiation therapy next month.
Just because a person is older, that doesn't mean that they should be denied medical care if they have a reasonable chance of an extended, high quality life.